dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/ShardedDOMDataTree.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.mdsal.dom.broker;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.collect.Iterables;
  12 import java.util.Collection;
  13 import java.util.Collections;
  14 import java.util.HashMap;
  15 import java.util.Map;
  16 import java.util.Set;
  17 import javax.annotation.concurrent.GuardedBy;
  18 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  19 import org.opendaylight.mdsal.dom.api.DOMDataTreeListener;
  20 import org.opendaylight.mdsal.dom.api.DOMDataTreeLoopException;
  21 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  22 import org.opendaylight.mdsal.dom.api.DOMDataTreeService;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  24 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingConflictException;
  25 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingService;
  26 import org.opendaylight.mdsal.dom.spi.DOMDataTreePrefixTable;
  27 import org.opendaylight.mdsal.dom.spi.DOMDataTreePrefixTableEntry;
  28 import org.opendaylight.mdsal.dom.spi.store.DOMStoreTreeChangePublisher;
  29 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  30 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33
  34 public final class ShardedDOMDataTree implements DOMDataTreeService, DOMDataTreeShardingService {
  35     private static final Logger LOG = LoggerFactory.getLogger(ShardedDOMDataTree.class);
  36
  37     @GuardedBy("this")
  38     private final DOMDataTreePrefixTable<ShardRegistration<?>> shards = DOMDataTreePrefixTable.create();
  39     @GuardedBy("this")
  40     private final DOMDataTreePrefixTable<DOMDataTreeProducer> producers = DOMDataTreePrefixTable.create();
  41
  42     void removeShard(final ShardRegistration<?> reg) {
  43         final DOMDataTreeIdentifier prefix = reg.getPrefix();
  44         final ShardRegistration<?> parentReg;
  45
  46         synchronized (this) {
  47             shards.remove(prefix);
  48             parentReg = shards.lookup(prefix).getValue();
  49
  50             /*
  51              * FIXME: adjust all producers and listeners. This is tricky, as we need different
  52              * locking strategy, simply because we risk AB/BA deadlock with a producer being split
  53              * off from a producer.
  54              */
  55         }
  56
  57         if (parentReg != null) {
  58             parentReg.getInstance().onChildDetached(prefix, reg.getInstance());
  59         }
  60     }
  61
  62     @Override
  63     public <T extends DOMDataTreeShard> ListenerRegistration<T> registerDataTreeShard(
  64             final DOMDataTreeIdentifier prefix, final T shard, final DOMDataTreeProducer producer)
  65                     throws DOMDataTreeShardingConflictException {
  66
  67         final DOMDataTreeIdentifier firstSubtree = Iterables.getOnlyElement(((
  68                 ShardedDOMDataTreeProducer) producer).getSubtrees());
  69         Preconditions.checkArgument(firstSubtree != null, "Producer that is used to verify namespace claim can"
  70                 + " only claim a single namespace");
  71         Preconditions.checkArgument(prefix.equals(firstSubtree), "Trying to register shard to a different namespace"
  72                 + " than the producer has claimed");
  73
  74         final ShardRegistration<T> reg;
  75         final ShardRegistration<?> parentReg;
  76
  77         synchronized (this) {
  78             /*
  79              * Lookup the parent shard (e.g. the one which currently matches the prefix),
  80              * and if it exists, check if its registration prefix does not collide with
  81              * this registration.
  82              */
  83             final DOMDataTreePrefixTableEntry<ShardRegistration<?>> parent = shards.lookup(prefix);
  84             if (parent != null) {
  85                 parentReg = parent.getValue();
  86                 if (parentReg != null && prefix.equals(parentReg.getPrefix())) {
  87                     throw new DOMDataTreeShardingConflictException(String.format(
  88                             "Prefix %s is already occupied by shard %s", prefix, parentReg.getInstance()));
  89                 }
  90             } else {
  91                 parentReg = null;
  92             }
  93
  94             // FIXME: wrap the shard in a proper adaptor based on implemented interface
  95
  96             reg = new ShardRegistration<T>(this, prefix, shard);
  97
  98             shards.store(prefix, reg);
  99
 100             ((ShardedDOMDataTreeProducer) producer).subshardAdded(Collections.singletonMap(prefix, shard));
 101         }
 102
 103         // Notify the parent shard
 104         if (parentReg != null) {
 105             parentReg.getInstance().onChildAttached(prefix, shard);
 106         }
 107
 108         return reg;
 109     }
 110
 111     @GuardedBy("this")
 112     private DOMDataTreeProducer findProducer(final DOMDataTreeIdentifier subtree) {
 113
 114         final DOMDataTreePrefixTableEntry<DOMDataTreeProducer> producerEntry = producers.lookup(subtree);
 115         if (producerEntry != null) {
 116             return producerEntry.getValue();
 117         }
 118         return null;
 119     }
 120
 121     synchronized void destroyProducer(final ShardedDOMDataTreeProducer producer) {
 122         for (final DOMDataTreeIdentifier s : producer.getSubtrees()) {
 123             producers.remove(s);
 124         }
 125     }
 126
 127     @GuardedBy("this")
 128     private DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees,
 129             final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
 130         // Record the producer's attachment points
 131         final DOMDataTreeProducer ret = ShardedDOMDataTreeProducer.create(this, subtrees, shardMap);
 132         for (final DOMDataTreeIdentifier subtree : subtrees) {
 133             producers.store(subtree, ret);
 134         }
 135
 136         return ret;
 137     }
 138
 139     @Override
 140     public synchronized DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 141         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees may not be empty");
 142
 143         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 144         for (final DOMDataTreeIdentifier subtree : subtrees) {
 145             // Attempting to create a disconnected producer -- all subtrees have to be unclaimed
 146             final DOMDataTreeProducer producer = findProducer(subtree);
 147             Preconditions.checkArgument(producer == null, "Subtree %s is attached to producer %s", subtree, producer);
 148
 149             final DOMDataTreePrefixTableEntry<ShardRegistration<?>> possibleShardReg = shards.lookup(subtree);
 150             if (possibleShardReg != null && possibleShardReg.getValue() != null) {
 151                 shardMap.put(subtree, possibleShardReg.getValue().getInstance());
 152             }
 153         }
 154
 155         return createProducer(subtrees, shardMap);
 156     }
 157
 158     synchronized DOMDataTreeProducer createProducer(final ShardedDOMDataTreeProducer parent,
 159             final Collection<DOMDataTreeIdentifier> subtrees) {
 160         Preconditions.checkNotNull(parent);
 161
 162         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 163         for (final DOMDataTreeIdentifier s : subtrees) {
 164             shardMap.put(s, shards.lookup(s).getValue().getInstance());
 165         }
 166
 167         return createProducer(subtrees, shardMap);
 168     }
 169
 170     @SuppressWarnings("checkstyle:IllegalCatch")
 171     @Override
 172     public synchronized <T extends DOMDataTreeListener> ListenerRegistration<T> registerListener(final T listener,
 173             final Collection<DOMDataTreeIdentifier> subtrees, final boolean allowRxMerges,
 174             final Collection<DOMDataTreeProducer> producers) throws DOMDataTreeLoopException {
 175         Preconditions.checkNotNull(listener, "listener");
 176         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees must not be empty.");
 177         final ShardedDOMDataTreeListenerContext<T> listenerContext =
 178                 ShardedDOMDataTreeListenerContext.create(listener, subtrees, allowRxMerges);
 179         try {
 180             // FIXME: Add attachment of producers
 181             for (final DOMDataTreeProducer producer : producers) {
 182                 Preconditions.checkArgument(producer instanceof ShardedDOMDataTreeProducer);
 183                 final ShardedDOMDataTreeProducer castedProducer = ((ShardedDOMDataTreeProducer) producer);
 184                 simpleLoopCheck(subtrees, castedProducer.getSubtrees());
 185                 // FIXME: We should also unbound listeners
 186                 castedProducer.bindToListener(listenerContext);
 187             }
 188
 189             for (final DOMDataTreeIdentifier subtree : subtrees) {
 190                 final DOMDataTreeShard shard = shards.lookup(subtree).getValue().getInstance();
 191                 // FIXME: What should we do if listener is wildcard? And shards are on per
 192                 // node basis?
 193                 Preconditions.checkArgument(shard instanceof DOMStoreTreeChangePublisher,
 194                         "Subtree %s does not point to listenable subtree.", subtree);
 195
 196                 listenerContext.register(subtree, (DOMStoreTreeChangePublisher) shard);
 197             }
 198         } catch (final Exception e) {
 199             listenerContext.close();
 200             throw e;
 201         }
 202         return new AbstractListenerRegistration<T>(listener) {
 203             @Override
 204             protected void removeRegistration() {
 205                 ShardedDOMDataTree.this.removeListener(listenerContext);
 206             }
 207         };
 208     }
 209
 210     private static void simpleLoopCheck(final Collection<DOMDataTreeIdentifier> listen,
 211             final Set<DOMDataTreeIdentifier> writes) throws DOMDataTreeLoopException {
 212         for (final DOMDataTreeIdentifier listenPath : listen) {
 213             for (final DOMDataTreeIdentifier writePath : writes) {
 214                 if (listenPath.contains(writePath)) {
 215                     throw new DOMDataTreeLoopException(String.format(
 216                             "Listener must not listen on parent (%s), and also writes child (%s)", listenPath,
 217                             writePath));
 218                 } else if (writePath.contains(listenPath)) {
 219                     throw new DOMDataTreeLoopException(
 220                             String.format("Listener must not write parent (%s), and also listen on child (%s)",
 221                                     writePath, listenPath));
 222                 }
 223             }
 224         }
 225     }
 226
 227     void removeListener(final ShardedDOMDataTreeListenerContext<?> listener) {
 228         // FIXME: detach producers
 229         listener.close();
 230     }
 231 }